Biology, Answering the Big Questions of Life/reproduction1

In humans there are two sexes: Men and Women. Babies are made when special cells called sperm (produced by men) combine with cells called eggs (produced by women) in a process called fertilization. Each of these cells is produced by a process called meiosis which makes cells containing half the information of the parent. When the cells combine, they form a new cell, called a zygote which has all of the information needed to make a new person. The zygote will grow to become a baby with a unique combination of his father's and his mother's traits.

The simplest answer is that they come from inside of the mother. In order for fertilization to occur, the father must enter his sperm into the mother's body by a process called copulation or sexual intercourse. The man inserts his penis into the female's vagina and the sperm cells swim into the mother's body.

They travel through the vagina and through the womb to the oviduct where fertilization usually takes place. The newly made zygote will divide rapidly to make a ball of cells called a blastocyst that will lodge in the womb and grow into a baby.

About 266 days after fertilization, a new baby will come out of the mothers vagina in a process called child birth.

Puberty is the time in a person's life when they first have the ability to create babies. For boys this is when they first produce sperm. For girls, this is after their first menstruation. Menstruation, sometimes called a period, happens when the lining of the womb sheds and a red blood like material flows out of the girl's vagina. Menstruation usually occurs once a month for women. Menstruation signals that a woman is releasing eggs that can be fertilized. The lining of the womb grows to prepare for the growth of a baby. If the egg is not fertilized that month, the womb will shed its lining and begin growing anew.

The time of puberty varies greatly and can be anywhere from age eight to about fifteen years. Typically puberty in girls happens at a younger age than in boys. After puberty a person's body changes from that of a child to that of an adult. In boys, they will grow hair in their groin, under their arms, on their chest and on their face. Their voice will drop in tone, and they will grow larger. For girls, their breasts will grow and their hips will widen, they will also grow hair in their groin and under their arms. It takes years before a person grows to their full adult size. This period of changing from a child to adult is called adolescence.